Swivel chair



FIG. 1 is a front perspective view of a swivel chair showing the new design;

FIG. 2 is a right side view thereof;

FIG. 3 is a is a left side view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a front view thereof; and,

FIG. 6 is a back view thereof. 

We claim the ornamental design for a swivel chair, as shown and described. 